It is known to use polycondensed elastomeric thermoplastic polymers and in particular copolyether-block-amides in the production of varied shaped articles (soles, belts, and the like), this being achieved by simple extrusion or by injection into a mold.
However, this technique presents problems of decomposition of the polymers during extrusion. This decomposition can be reflected in particular by a discoloration, a fall in the molar mass and an accelerated aging of the products.
There thus exists a real need to develop a process for the conversion of a polycondensed elastomeric thermoplastic polymer in which the decomposition of the polymer during extrusion is reduced.
The document EP 1 037 941 describes the extrusion of a composite preparation comprising polyamide and a solid substance of clay type, in the presence of water, with the aim of avoiding a preliminary stage of exfoliation of the clay. This document does not make it possible to solve the problem posed, if only because the polyamide is not an elastomer.